The invention relates to an improved developing device in electrophotographic copying apparatus.
In a wet developing process, a developing solution is supplied across a photosensitive member to develop an electrostatic latent image thereon. It is known to dispose a developing electrode within the developing solution in opposing relationship with the photosensitive member and to apply a bias voltage to the developing electrode in accordance with a residual potential on the photosensitive member, thereby preventing a background smearing. However, in the known process, the bias voltage applied to the developing electrode is, by several tens of volts, higher than the residual potential on the photosensitive member, so that an adhesion of toner to the electrode may occur, thereby reducing the intended electrode effect.